The present invention relates to isocyanate addition products and to a process for their production.
Phosphorus-containing flame retardants have been used for some time in the production of plastic materials based on isocyanates such as polyurethane and polyisocyanurate plastic materials, including foams. Trichloroethyl phosphate and dimethylmethane phosphonate (DMMP) are common flame retardants.
The trichloroethyl phosphate flame retardants frequently cause a blowing agent (for example, trichlorofluoro-methane) to be sparingly soluble in the polyol mixture. The DMMP flame retardant leads to good solubility for the blowing agent, but can be used only in low concentrations because it makes the finished foams very flexible and also gives off strong odors during processing.